Biomedical subjects

E Kobyliansky

Publications and source records attributed to E Kobyliansky.

At least 37 records · Page 2Linked to original sources

PubMed2000

Quantitative genetic analysis of circulating levels of biochemical markers of bone formation.

Carboxyterminal propeptide of type 1 collagen (PICP) and bone Gla-protein-osteocalcin (BGP) are the most important components of the organic bone matrix and play a key role in bone formation. To investigate whether and to what extent variation of the plasma levels of these indices of bone turnover depends on genetic factors, we studied 355 adults belonging to nuclear pedigrees. Genetic analysis was carried out in 2 steps: 1) variance decomposition analysis was performed using the FISHER statistical package; and 2) complex segregation analysis implemented in the program package MAN. The effect of age and gender differences, gender hormones, as well as PTH and vitamin-D (calcidiol) plasma levels were evaluated simultaneously with the parameters of variance analysis. The results showed that about 50% of PICP variation is attributable to genetic factors. The effect of age was significant among men and postmenopausal women, whereas calcidiol influenced variation of PICP in premenopausal women. The results of variance analysis showed that some 40% of BGP, adjusted for confounding variables, can be explained in genetic factors. Age and PTH were important covariates for osteocalcin in men and premenopausal women. Exploration of the maximum likelihood estimates of the various hypotheses concerning the mode of intergenerational transmission of PICP and BGP demonstrated a good correspondence to the Mendelian mode of inheritance (i.e., major gene effect).

Adolescent↗

PubMed2000

Evidence of major gene control of cortical bone loss in humans.

Cortical index (CI) is the ratio of the combined cortical thickness to the total diameter of the bone. It serves for the assessment of the geometric properties of bone and for indirect evaluation of bone mass. CI is a useful predictor of osteoporosis. The aim of the present study was to test the hypothesis of major gene control of CI variation in a large sample of pedigrees from Chuvashia, Russia. Complex segregation analysis revealed that the major gene model of CI inheritance is the best fitting and most parsimonious for the present data. Parameters of the genotype-gender specific dependence of CI variation on age were estimated simultaneously with other parameters in the segregation analysis. The results of analysis showed that not only the baseline level of CI but also the age at onset of the involutive bone changes (inflection point) and the rate of the CI decrease with age (slope coefficient) are under control of the same major gene. Non-major gene effects shared by pedigree members (residual familial correlations) were found to be statistically insignificant. Approximately 73% of inter-individual variation in CI was attributable to the effects explicitly included in the model.

Adolescent↗

PubMed2000

Use of the hand bones roentgenographs in the prediction of age in nine human populations.

The major aim of this study was to develop an accurate method of age prediction for a wide range of ages, based on the roentgenographic assessment of the hand bones, for use in paleoanthropology and forensic medicine. The roentgenographs of the hand bones were assessed in 5756 individuals, 2683 males and 3073 females, aged 17-93 and 17-89, respectively, belonging to 9 ethnic groups from the former USSR, Israel, and Sinai peninsula (Egypt). For each roentgenogram an equidistant osteographic score (OSS) including the descriptive criteria of bone age, such as (1) osteophytes or nodes of Heberden in the periarticular regions and at sites of tendon attachment, (2) manifestations of osteoporosis, (3) signs of sclerosis, and (4) non-traumatic articular deformities, was estimated. Regression analysis, that included linear, non-linear, logistic, and stochastic models, was used to evaluate the relationships between age and OSS. This relationship was best described by a logistic regression function. Results of the logistic regression analysis clearly indicate that OSS is a strong predictor of an individual's age, with r2 values ranging from 0.671 to 0.901 (p < 0.001). Our standard errors of estimate were ranging from +/- 4.2 to +/- 7.3 years, comparing favorably with most known methods of bone age assessment. This study provides an efficient method of age prediction, which allows to extend the upper limit of prediction to the age of 70 years with acceptable accuracy.

Adolescent↗

PubMed1999

Segregation analysis reveals a major gene effect in compact and cancellous bone mineral density in 2 populations.

Involvement of genetic factors in determining bone mineral density (BMD) is doubtless. However, the exact nature of the genes governing BMD variation and sources for genetic determination of BMD of different parts of bone (compact and cancellous) have not been completely studied. The results of the complex segregation analyses performed in our previous study (Livshits et al. 1996) on a Turkmenian sample strongly support the hypothesis that a single Mendelian locus has a large effect on BMD. The parameter estimates for both types of bone tissue were so similar that we could assume a common gene effect for BMD variation of cancellous and compact bone. The objectives of the present study are to test again the possibility of major gene control of BMD in a different ethnic sample of pedigrees, namely, the Chuvasha. In addition, we report here the results of a bivariate segregation analysis of compact and cancellous BMD performed in both the Turkemenian and the Chuvasha samples of pedigrees. The results of the present study closely resemble the results obtained on the Turkmenian pedigrees. Likewise, the major finding of the present study is that there is a significant major gene effect on both compact and cancellous BMD; polygenic hypotheses were clearly rejected. Moreover, the results of the bivariate segregation analysis in both the Chuvasha and Turkmenian samples were similar. They lead to acceptance of the hypothesis that there is a single major locus with pleiotropy to both compact and cancellous bone.

Adolescent↗

PubMed1999

Relationship between genetic anomalies of different levels and deviations in dermatoglyphic traits. Part 6: Dermatoglyphic peculiarities of males and females with cleft lip (with or without cleft palate) and cleft palate--family study.

The present study was carried out to evaluate the effect of polygenic morbidity with respect to Cleft Palate and Cleft Lip with or without Cleft Palate (CL) in males and females based on dermatoglyphic traits (DT) and indices of intraindividual diversity (Div), fluctuating (FA) and directional (DA) asymmetry. The main objectives of the present study were as follows: a) to find DT and FA indices, which could be "marker" traits and could indicate the degree of developmental instability of the organism; b) to explore the possibility of using DT, FA, Div and DA indices of CL patients and their parents and to predict the likelihood of the disease appearing in the offsprings of apparently healthy individuals. The samples were of 106 CL patients (59 males and 47 females) and 156 of their parents (67 fathers and 89 mothers), all Israeli Jews. The prints were collected in the Beilinson (Petah-Tikva) and Rambam (Haifa) and Hadassah (Mount Scopus, Jerusalem) Hospitals, or in the abodes of the CL patients. The results were compared with the control group of healthy women and men whose data are detailed in our previous publication. Interpretation of the prints were done according to the methods and included identification of patterns, ridge counts and the measurements of distances and angles in the palms, 79 DT for every individual, 28 continuous traits, 9 discrete traits, 11 indices of Div, 15 DA indices and 16 FA indices. In CL groups increased FA indices values were found and a decreased sexual dimorphism in DT of the CL and parental groups as compared to the control--this both in terms of the number of significant differences, as well as in values of the traits (e.g. smaller differences between the male and female values). The above mentioned findings were partly confirmed also by the discriminant analysis. The values of DT parents were generally similar to those of the control. The best discrimination was obtained between the CL and control groups (70.44% between CL males and control males and 83.47% between CL females and control females). Over 50% of the DT variables were found to be suitable for including into the discriminant function.

Adolescent↗

PubMed1999

Heterogeneity of genetic control of blood pressure in ethnically different populations.

We review the literature on statistical genetic analyses of blood pressure in samples from various ethnic backgrounds using different statistical methods and packages. We then provide the results of a complex segregation analysis performed on familial data on systolic and diastolic blood pressure in 2 ethnically different populations, Chuvashans and Turkmenians. Two types of major gene models were tested in the segregation analysis: Model type 1 tests for a Mendelian mode of transmission and estimates genotype-specific averages regardless of age and sex effect, and model type 2 estimates age and sex effects on each of 3 genotypes within the putative major genotype. In both total samples, by both types of segregation analysis, familial aggregation of both systolic and diastolic blood pressure was inconsistent with the Mendelian mode of inheritance. In the next step of analysis the pedigrees in both samples were sorted into 2 groups on the basis of 2 likelihoods as obtained under Mendelian and nontransmission models for each entire sample. This procedure resulted in the appearance of 2 subsamples (large and small) in each ethnic sample. The segregation analysis that was carried out then on the larger subsample provided consistent evidence to support the major gene effect on systolic and diastolic blood pressure in 2 ethnic groups. Interestingly, model type 2 showed that in both ethnically different large subsamples, for each sex the genotype predisposing to a larger mean value of systolic (or diastolic) blood pressure also displayed the highest rate of blood pressure increase with age. We discuss in detail possible sources of heterogeneity in familial transmission of blood pressure observed in our 2 samples, and we suggest a method to improve the analysis of heterogeneity for trait inheritance.

Adolescent↗

PubMed1999

Relationship between genetic anomalies of different levels and deviations in dermatoglyphic traits. Part 4: Dermatoglyphic peculiarities of males and females with Down syndrome. Family study.

The present study was carried out in order to evaluate the effect of chromosomal morbidity (trisomy 21) in males and females with Down's Syndrome (DS) based on dermatoglyphic traits (DT) and their indices of diversity and asymmetry. The results were compared between parents and control groups of women and men whose data are detailed in our publication (Kobyliansky et al. 1999). The general aim of the study was to explore the possibility of using DT of the parents of DS patients to predict the likelihood of the disease appearing in the offspring. The samples were of DS patients (198 males and 140 females) and their parents (84 fathers and 153 mothers), all Israeli Jews. The prints were collected in the Genetic Institute of the Sheba Hospital, Ramat-Gan, Israel, and were validated by chromosomal examination. Interpretation of the prints was done according to Cummins & Midlo (1961) and Penrose (1968) and included identification of patterns, ridge counts and the measurements of distances and angles in the palm of the hands; 79 DT for every individual: 28 continuous traits, 9 discrete traits, 11 indices of intraindividual diversity (Div), 15 indices of directional asymmetry (DA) and 16 indices of fluctuating asymmetry (FA) were estimated. This study supports the hypothesis that the magnitude of FA in groups with low developmental stability (groups with chromosomal aberrations) or other birth defects, is elevated, compared with FA in healthy controls. The present study found proof of the existence of an additive genetic component in the FA of DT, while an increased FA was observed in parents of DS patients in comparison to control groups. The DT which are typical to DS patients were confirmed also in parents. The decrease in sexual dimorphism of the DT was found in DS patients and their parents in comparison with the control.

Adult↗

PubMed1998

Aging bone score and climatic factors.

Hand radiograms for osseographic assessment of bone aging status were taken from more than 7,500 individuals residing in 31 different localities and belonging to 20 ethnic groups. Multiple regression analysis was used to evaluate possible associations between bone aging parameters and several climatic factors, to wit: hours of daylight in January and July, average monthly humidity and partial vapor pressure in January and July, and one climatic index pertaining to comfort conditions in life, namely, the Bioclimatic Index of Severity of Climatic Regime. Multiple regression analysis clearly pointed to significant correlations between climatic characteristics and indices defining the relative rate of bone aging in humans; it also evinced an independent contribution of July's humidity and January's mean temperature to earliest age at which first signs of bone aging can be found. In sum, there are grounds for concluding that temperature and humidity are key factors in triggering initial bone changes in individuals within the human populations prone to environmental effects. The combination of humidity and temperature with other factors which reflect the sharpness of the interseasonal differences in climatic conditions predispose the populations to early onset of bone changes.

Adolescent↗

PubMed1998

Fluctuating asymmetry and morphometric variation of hand bones.

The major aim of this study was to test three hypotheses: 1) more complex traits of the hand are less prone to developmental insults and therefore show lower fluctuating asymmetry (FA) as compared with simple traits; 2) the manifestation of FA correlates with the variability of the trait (i.e., CV); and 3) FA is an organ-wide property, and therefore a concordance exists between the FA measures of different traits in hand bones. Seventy-two bilateral measurements of hand bones, were made from plain-film radiographs of 365 cadavers. A complex trait was considered as the total length of the three phalanges of a finger and their contiguous metacarpals. Simple traits were considered to be the lengths of individual bone that made up the complex trait. The following results were obtained: 1) on the average simple traits, composing the complex trait, show much higher FA than the corresponding complex trait, but this result is expected if there is no correlation (or low correlation) between FA of simple traits within the complex trait, due to random direction of right-left differences; 2) strong and highly significant correlation was observed between FA and CV of studied traits, regardless of sex and age of individuals; and 3) the majority of FA measurements of hand bones showed no correlation. However, correlations between some sets of FA traits were highly significant. They were interpreted, although not specifically tested, as the result of a tight relationship between traits related not only developmentally but also by active performance of the same function.

Adolescent↗

PubMed1998

Major gene control of human body height, weight and BMI in five ethnically different populations.

Pedigree samples were collected from five ethnically and geographically different populations: Kirghizians, Turkmenians, Chuvashians, Israelis and Mexicans. All studied individuals were assessed for body height, weight and BMI. The sample size in the studied pedigrees ranged from 381 to 1811 individuals. Segregation analysis of these traits preliminarily adjusted for sex and age was performed by means of program package MAN that provides parameter estimates for the major gene effects, for the residual within the genotype correlations between relatives and for the assortative mating. By the usual transmission probability tests, the 'environmental' model was strongly rejected for all measured traits in all 5 populations. The major gene mode of inheritance, however, was accepted for all traits. The results of analysis in 5 populations were remarkably similar, and showed that except for Mexican sample, the proportion of variance attributable to major gene effect ranged between 37 and 53% for body weight and height. In the Mexican sample it explained only about 14% of the body weight variation. The proportion of inter-individual variation in BMI attributable to major gene effect was consistently lower in all populations in comparison with height and weight and ranged between 17 and 40%. Strong assortative mating in body height, as estimated by correlation between putative major gene genotypes in spouses, was found in four populations, not including Mexican pedigrees.

Adolescent↗

PubMed1997

Relationship between genetic anomalies of different levels and deviations in dermatoglyphic traits. Part 2: Dermatoglyphic peculiarities of females with Turner's syndrome.

The present study is carried out to evaluate the effect of chromosomal morbidity (45x/46xx or 45x/47xxx or 45x) in the females with Turner syndrome, based on dermatoglyphic traits and indices of diversity and asymmetry. The main objectives of the present study is to find dermatoglyphic traits and fluctuating asymmetry indices which could be "marker traits" and could indicate the degree of developmental instability of the organism. The sample of Turner females (N = 57) was collected in the Genetic Institute of Sheba Hospital, Tel Aviv, Israel, by Professor Bat-Miriam Katznelson during 20 years, between 1968-1988. All patients were checked by chromosomal examination and finger and palm prints were collected with the aid of pads manufactured by Lamedco Inc. Knoxville, Tennessee, U.S.A. Interpretation of the prints was according to Cummins & Midlo (1961) and Penrose (1968) and included identification of patterns, ridge counts and the measurements of distances and angles in the palms. 79 dermatoglyphic variables for every patient: 28 continuous traits, 9 discrete traits, 11 indices of intraindividual diversity, 15 indices of directional asymmetry and 16 indices of fluctuating asymmetry were estimated. The problem of asymmetry, fluctuating and directional and of intraindividual diversity of quantitative dermatoglyphic traits is here reviewed as well as illustrated by data obtained on a sample of healthy control group of Jews from Israel.

Adolescent↗

PubMed1996

Population biology of human aging: segregation analysis of bone age characteristics.

The main goal of the present study is to elucidate the extent to which primary characteristics of bone aging are determined by major gene effects. We report the results of a complex segregation analysis of bone mineral density (BMD) and osseographic score (OS) carried out on an array of pedigrees from rural Turkmenia. Both variables showed a significant correlation with age and thus were adjusted. However, the correlations with body height, weight, body mass index, and obesity indexes were negligible. The results of the segregation analysis performed on BMD clearly indicate major gene effects on BMD variation. The Mendelian transmissibility hypothesis with two codominant alleles was chosen as the best-fitting and most parsimonious model. Under this hypothesis 50-60% of total variation in BMD, depending on bone area, can be attributed to a major gene effect, and the frequency of the allele determining the higher value of bone density is between 30% and 38% in the Turkmenian population. Regarding the OS, segregation analysis provided evidence supporting intergenerational transmissibility of this characteristic and yet the Mendelian model was rejected.

Adolescent↗

PubMed1996

Population biology of human aging: ethnic and climatic variation of bone age scores.

Hand radiograms for osseographic assessment of bone-aging status were taken from more than 7500 individuals living in 32 different geographic localities and belonging to 20 ethnic groups. Multiple regression analysis was used to evaluate possible associations between bone-aging parameters and number of climatic factors. To determine whether population differences in bone-aging estimates were related to linguistic, ethnic, or genetic differences among the samples, we performed a matrix correspondence analysis. Euclidean distance matrices for parameters TM (average age at entering visual stage of bone aging) and B (the rate of bone aging per year) were tested against design matrices specifying linguistic or ethnic affiliation of the tested populations, yet no significant correlations were detected in this set of analyses. The matrix of joint genetic distances based on 10 genetic systems showed significant correlation (r = 0.48, p = 0.013) with the matrix of B differences. This suggests some genetic control in the rate of bone aging. TM and age-adjusted bone-aging scores (Z) yielded no evidence of correlation with genetic differences among the studied populations. Multiple regression analysis, however, uncovered that 37.5% of TM variation and 48% of Z variation could be explained by climate factors and their interactions.

Age Determination by Skeleton↗

PubMed1996

Bilateral asymmetry in dental discrete traits in human isolates: south Sinai Bedouin tribes.

Data are presented on dental morphology as adjudged from dental casts of children (boys and girls) 6-13 years of age from four Bedouin tribes of Southern Sinai (Gebeliya, Muzeina, Hamada and Aliquat) and a mixed group designated as "other tribes", (Awlad Said, Gararsha, Sawalcha, Haweitat and Beni-Wassal). Alginate was the impression material used and the casts were made of artificial stone poured into the irreversible hydrocolloid impression. A total of 352 casts were available for study. In the maxilla, 29 dental discrete traits of permanent teeth and 2 traits of deciduous teeth were observed, and in the mandible, 24 traits of permanent teeth and 2 traits of deciduous teeth; in all, 57 traits were observed. Only clear traits were considered. From the studied 57 traits only 30 morphological traits were used for the estimation of the asymmetry. Total symmetry was observed in 2 mandibular teeth and traits: a) Lateral incisor-LI-slight inclination; b) Canine-Cn-no lingual cingulum and in 3 maxillary teeth and traits a) Central incisor-CI-slight convexity of labial profile curvature; b) First premolar-PM1-intercuspal distance more than 3 mm; and c) Second molar,-M2-pit groove pattern similar to the first molar. Low values of asymmetry (1-5.1%) were observed in traits describing outline form and shape, surface outline, and number of cusps in three maxillary and two mandibular teeth (nine discrete traits). High values of asymmetry (12.7-37.0%) were observed regarding traits describing styles on slopes, ridges, pits, grooves and lingual tubercles in three maxillary and one mandibular teeth (15 discrete traits). The high rate in molars was higher than that in the incisors. A higher rate of asymmetry occurred in the maxilla than in the mandible.

Adolescent↗

PubMed1995

Population biology of human aging: methods of assessment and sex variation.

Biological age, as assessed by osteographic measurements of hand bones from radiograms, was estimated in about 7000 individuals belonging to 32 ethnic groups and samples and to 2 major human groups (Europeans and Asians). Individual ages in the total group varied between 16 and 99 years old. Our biological age measure is strongly correlated with chronological age of the individual (Pearson's r = 0.78-0.80, p < 0.001), which renders the correlation amenable to fitting with a two-stage stochastic model. The following parameters of the model were estimated accordingly: t0 is the minimal age at which initial bone changes occurred, q is the probability that an individual will first develop involutive bone change at age ti > t0, and B is the rate of aging (bone change) per unit time. The parameters varied considerably within different populations, but only a few samples showed statistically significant sex differences for all three parameters. However, B was consistently higher among women than among men. Apart from that, the distributions of the observed biological age estimates adjusted on the expected biological age values reveal no differences between men and women in any of the studied samples or in the total population.

Adolescent↗

PubMed1994

Biology of aging in an Israeli population. 2. Polymorphic blood markers and fluctuating asymmetry.

The major objectives of the present study were to detect whether there are any differences in genetic blood markers distribution between the young and old Israeli population. We also investigated the question about the relationship between the genetic heterozygosity (H) and fluctuating asymmetry (FA) of an individual. The study sample consisted of 208 elderly people aged between 75 and 94 years old. Each individual was assessed for the same 18 anthropological traits, 8 of which were paired bilateral structures and 10 were size and mass measurements. Thirteen polymorphic gene markers were also taken from each individual. Most of the studied gene systems showed no inter-group (old sample vs 207 young individuals) differences. Significant differences were detected at ADA, ESD, GTP1 and FY loci. These differences were mainly due for the considerably lower frequency of the heterozygous individuals in elderly samples. Our working hypothesis at the next stage of the analysis were as follows: 1. Morphologically central phenotypes are more symmetric (processes lower FA) than morphologically extreme individuals. 2. There is a detectable negative correlation between the FA and individuals H. To study these questions we developed a multivariate measure of FA and morphological deviation of the individual from the population centroid. Yet, no reliable evidence in support of either of the two hypotheses were obtained.

Adult↗

PubMed1993

Variables affecting dental fluctuating asymmetry in human isolates.

The aims of the present study are to 1) determine and describe levels of dental fluctuating asymmetry (FA) in a highly endogamous human group; 2) evaluate the effects of various FA measures on perceived FA levels and their interrelationships; 3) study the connections between dental variables (tooth size, class, position, type, location and dimension) and FA levels; and 4) estimate the interrelationships between dental FA measures. The study was carried out on 242 Bedouin boys aged 5 to 14 years. The results demonstrate that the main variables influencing dental FA levels within this population are tooth class (incisors, canine, premolars, molars) and position (mesial, distal) and that the interaction between the two is significant. When sample sizes are large enough and individual measures are needed for the statistical analysis, the use of a computational method based on absolute values is legitimate. Clear relationships between some FA dental traits are discerned through principal-components analysis.

Child↗

PubMed1991

Fluctuating asymmetry as a possible measure of developmental homeostasis in humans: a review.

We investigate three hypotheses related to fluctuating asymmetry (FA) of bilateral morphologic traits in humans: (1) the magnitude of FA in individual suffering from different levels of morbidity is significantly elevated compared with FA in healthy control subjects, (2) FA is negatively correlated with an individual's heterozygosity, and (3) phenotypic variance of FA may have a significant genetic component (or at least a family resemblance). Our experimental data and the literature support the first hypothesis and indicate that individuals who suffer from chromosomal or polygenic morbidity and from anomalies or conditions of development with still unknown genetic components demonstrate an elevated FA of various structures. The literature regarding the second hypothesis is sparse but is generally in agreement with it, although some exceptions exist. A study of correlations of phenotypic scores of FA between family members of nuclear families in two independent samples has shown that FA variance in individual traits probably does not have any significant genetic component. However, phenotypic variance of the mean estimate of FA over 8 traits showed significant additive and nonadditive (dominance) genetic components, each about 0.30.

Anthropometry↗